Method of manufacturing a cotton fiber-like material from straw



Patented Dec. 29, 1936 UNITED STATES PATENT OFFICE METHOD OF MANUFACTURING A COTTON FIBER-HIKE MATERIAL FROM STRAW Soai Tanaka, Sakyo-Ku, Kyoto, Japan 1 Claim.- (CI. 92-10) The present invention relates to a method of manufacturing a cotton fiber-like material from straw, which consists in a heating a-cellulose,

which is obtained by digesting the straw with alkali, with the addition of "Nib" (the liquor extracted from the vegetable glue, Hydrangea paniculata szet" utilized as a sizing material in making Japanese paper) and myrrh, and after gelatinizing it by treatment with hydrosulphites 0 such as rongalite (CH20.NaHSOz.HzO), bleaching it with a bleaching powder and then adding ammonium carbonate and collecting the stable fiber. The object thereof is to obtain very simply from the straw a cotton fiber-like material suit-' able as the material for gun cotton or for use in medical treatment.

It is known that a-cellulose may be obtained by heating a graminaceous plant for long hours inabout of caustic soda; see, for example, the Chemistry of Cellulose and Wood by Shorger, p. 539, 1926. However under microscopic examination such a product is found to be impure cellulose havinga bundle shape and containing a large quantity of impurities, and although it is an interesting question how it may be turned into a cotton-like material, it has hitherto been. the practice to change the'straw treated with caustic soda into a cotton-like material by simply beating it mechanically and then bleaching it with a bleaching powder or chlorine gas. The yield reaches about 30% of the raw material, but it is unavoidable that the product should be very impure cellulose having an irregular form like a sparrow's nest. Now, according to the present invention, after heating a-cellulose obtained by digesting the straw with' caustic alkali or the like with the addition of Nib and myrrh, it is treated with hydrosulphites such as rongalite and gelatinized. Next, it is decolorized with a bleaching powder, viz. calcium hydrochlorite or chlorine gas and then is mixed with ammonium carbonate so that the fiber bundle swells up and opens into single fiber and thus can be collected as a cotton fiber- 5 like material consisting of cellulose of high purity.

"Nib employed in this invention is a liquor extracted from the vegetable glue (Hydrangea paniculata siet) utilized as a sizing material in 50 the making of Japanese paper. The thin fibers are connected together by covering the surface of the fibers with the above Nib'k and myrrh, namely resin acids largely consisting of commiphuric acid is dissolved by the remaining alkali 55 attached to the fiber, whereby the fiber is given tenacity and elasticity. After thus receiving a preparatory treatment, it is gelatinized with hydrosulphites and easily swells up and opens into single fiber by ammonium carbonate. In 00 short, by the combination of these steps the noncellulose material is removed easily and the bundle-shaped fiber is changed into single fiber of high purity. Although the ratio of the yield with reference to the raw material, the straw, is

somewhat small, it has high purity and therefore 5 is very suitable not only as the material for gun cotton, but as a substitute for absorbent cotton for use in medical treatment on account of its great adsorbing property. Being in theshape of a straight tubular filament instead of in a curled 10 condition, the fiber if used as spinning material, must be mixed with over about 3% of cotton or wool and subjected to so-called mixed spinning.

The following are examples illustrating this invention.

Example I Heat 10 kilograms of the straw for more than 10 hours with the addition of the same quantity of caustic soda and a suitable quantity of water, and digest it sumciently. After adding 250- grams of Nib" to a-cellulose obtained by filtering and washing the above material, turn the mixture into a slightly alkaline state with a substance such as sodium peroxide and heat it at 25 "40-50" C. for about 2 hours with the addition of a Example II Add'2 kilograms of calcium oxide and a suitable quantity of water to 10 kilograms of the 40 straw and heat it in an autoclave under pressure for 10 hours, separate a-cellulose therefrom and carry out the same operation as in Example I. This eflects an economy in the consumption of caustic soda.- In this case, chlorine gas may be employed in lieu of a bleaching powder.

I claim:

Method of manufacturing a cotton fiber material comprising heating a-cellulose, which is obtained by digesting straw with alkali, with the addition of Nib" (the liquor extracted from the vegetable glue, Hydrangea paniculata siet" utilized as a sizing material in the making of Japanese paper) and myrrh, then gelatinizing it by treatment with hydrosulphites, bleaching it with chlorine, and then adding ammonium carbonate whereby it is opened into single fiber form. I

SOAI TANAKA. 00 

